NEW YORK — The Stagwell Group — the investment group founded last year by former Clinton aide Mark Penn — has bought a minority stake in Finn Partners while also creating a joint PR venture with the firm.

As part of the deal, the Stagwell Group purchased preferred stock in Finn Partners carrying future conversion rights to a minority interest in the firm. "As this is a minority investment, there is no change in management, structure or operations of Finn Partners. Stagwell Group’s managing partner Mark Penn will join Peter Finn on the Finn Partners board," the firm said in a statement.

In addition, the Stagwell Group and Finn Partners are creating a jointly-owned firm Wye Communications that will be a conflict shop for Finn and provide PR services for Stagwell's clients. Stagwell will have a controlling interest in the firm that will be US-based while servicing clients globally.

In 2015, Finn Partners generated about $71m in revenues (up 35% from the year prior), enough to rank as the number six independent in the US. Most of the revenue comes from the US and technology is Finn's largest practice area.

The Stagwell Group was formed in June 2015 by former Burson-Masteller chief executive Penn, who also serves as the managing partner of Stagwell Media. Former Microsoft chief executive Steve Ballmer—with whom Penn worked in a senior advisory role at the software giant—is a core investor and the group has raised $250 million in capital and may leverage that to make up to $750 million in acquisitions.

Last fall, Stagwell acquired strategic communications and public affairs firm SKDKnickerbocker through its Stagwell Media private equity fund. Meanwhile, Finn has been on an acquiring spree over the last two years buying firms that include the Horn Group, Lane PR and Greenfield Belser.